1. Field of the Invention
This invention relates to a dual reflector lighting system or luminaire having an outer reflector and an inner reflector and an adjusting assembly for independently adjusting each of the inner and outer reflectors. The use of the dual reflector system increases the efficiency of the fixture such that 250 watt fixtures can replace 400 watt fixtures without any loss of light at the working plane. This results in a substantial energy saving. The subject invention allows the inner and outer reflectors to be adjusted independently of each other, which gives great versatility to the fixture to allow it to be used in many applications of varying heights and spacings and achieve optimum results. The inner reflector and outer reflector are mounted concentrically and are adjusted in such a way as to prevent cocking and to maintain concentricity. The invention also includes the adjusting assembly for independently adjusting an outer reflector and an inner reflector relative to a high intensity discharge lamp. The adjusting assembly includes an elongated adjusting member having one end mounted to the outer reflector and the other end mounted to the casing or housing for the ballast. Facilities are provided for adjusting the inner reflector relative to the adjusting member. Facilities are also provided to adjust the outer reflector relative to the adjusting member. The invention also covers a dual reflector assembly including an inner and an outer reflector and an adjusting assembly for allowing independent adjustment of each reflector relative to the adjusting assembly. The invention also covers a retrofit kit for retrofitting conventional fixtures to become dual reflector fixtures.
2. Description of Related Art
Thomas et al. U.S. Pat. No. 5,582,479 discloses a dual reflector lighting system having an outer reflector and an inner reflector. The inner and outer reflectors are adjustable relative to each other by a plurality of screws. The outer reflector is adjustable by a bracket, but movement of the outer reflector also moves the inner reflector. An alternative embodiment discloses a bracket assembly for the inner reflector which is adjustable about the lamp socket. In view of the fact that the subject invention is an improvement of this patent, all of this patent is incorporated herein by reference.
Henderson Jr., et al U.S. Pat. No. 4,173,037 discloses a luminaire lamp support device in which the lamp socket is adjustably mounted on a bracket for adjustment of the socket along a substantially vertical axis. This enables adjustment of the lamp to different positions to obtain various light distribution patterns. The lamp has an outer reflector and an asymmetric inner reflector which is mounted for rotational adjustment about the vertical axis of the luminaire for producing asymmetric distribution of reflected light.
Sholtz U.S. Pat. No. 5,178,452 discloses an operating theater lamp with a outer reflector which illuminates the area of operation and an auxiliary reflector having an outer diameter which corresponds approximately to the inner diameter of the outer reflector and which is arranged inside the outer reflector to deflect a part of the light beam at a steeper or narrow angle into the bottom of a surgical wound.
Wijbenga, et al U.S. Pat. No. 5,251,116 discloses a luminaire for creating a primary beam and a secondary beam.
Baldwin, et al U.S. Pat. No. 4,943,901 discloses a luminaire with auxiliary reflecting means for reflecting light passing through the top opening and for reflecting such light to illuminate stacked material along the edges of the aisle.
Compton U.S. Pat. No. 4,231,080 discloses a luminaire having at least three stack reflector members.
Cochran U.S. Pat. No. 1,286,535 discloses a lighting fixture having a outer reflector and a stationary auxiliary reflector.
None of the foregoing prior art have suggested a lighting fixture having an inner reflector and an outer reflector and an adjusting mechanism that allows for the adjustment of both the outer reflector and the inner reflector independently of each other.
The present invention fills a need for an energy efficient high bay lighting fixture or luminaire which enables fixtures having lamps of reduced wattage to be used to replace higher wattage fixtures thereby conserving significant amounts of energy. Typically, the replacement of a 400 watt luminaire with a 250 watt luminaire will result in an approximately 40% or greater savings in energy. The present invention relates to a luminaire having a high intensity or gaseous discharge lamp which is mounted with the base up or down in a substantially vertical position. An inner reflector is mounted to an adjusting assembly for coaxial movement relative to the lamp. The inner reflector is adjustable along the longitudinal axis of the lamp so that a substantial amount of light is reflected from the inner reflector onto a first predetermined area while a smaller amount of light is reflected from the outer reflector onto a second predetermined area outside of the first area. The first predetermined area is an area substantially larger than the outer diameter of the outer reflector. It is typically an area that is equal to or greater than the width of an aisle and usually averages fifteen to thirty feet in diameter.
In one embodiment of this invention, a threaded elongated adjusting member having at least two and preferably three equidistant longitudinal grooves formed therein has one end attached to the casing of a high intensity discharge fixture. The casing contains the ballast assembly which includes a ballast, capacitors, and ignitors if required, as is well known within the art. The adjusting member has a hollow portion in the bottom into which a lamp socket is secured. Preferably, the lamp socket is fully recessed within the adjusting member. The wires from the lamp socket run through the adjusting member and are connected to the ballast in the casing. An outer reflector having a threaded adjusting ring or member connected to the top thereof with threads complementary to those of the adjusting member is mounted to the lower end of the adjusting member. The outer reflector can be adjusted to any desired position on the adjusting member by rotation of the adjusting ring. A plurality of elongated members or rods which fit into the grooves of the adjusting member have their lower ends connected to an inner reflector. The upper ends of the rods are offset or flanged to engage the upper surface of another threaded adjusting ring which, upon rotation, moves the rods up and down in the grooves along the length of the adjusting member.
In another embodiment of this invention, a dual reflector adjusting assembly is provided which includes a smooth adjusting member with a plurality of equidistant longitudinal grooves, preferably three, formed therein. A first clamp, which is connected to the top of the outer reflector, is adapted to move about and clamp on the lower end of the adjusting member to position the outer reflector at a desired location. A plurality of rods which ride in the grooves of the adjusting member have their lower ends connected to an inner reflector. A second clamp is adapted to move about the adjusting member and engage the upper ends of the rods. When the desired position of the inner reflector is obtained, the clamp is secured to the adjusting member to lock in the position of the inner reflector.
In another embodiment of this invention, a tubular adjusting assembly has a smooth adjusting member without any grooves formed therein. A first clamp is mounted to the outer reflector and is adapted to move along the adjusting member and be secured at a desired position for setting the outer reflector. A second clamp has a plurality of rods fixed thereto, the lower ends of which are connected to the inner reflector, and the upper ends of which are connected to the second clamp. This second clamp is moved and positioned along the adjusting member for adjustment of the inner reflector.
Further aspects of the present invention will become apparent from the following detailed description when considered in conjunction with the accompanying drawings. It should be understood, however, that the detailed description and the specific examples while representing the preferred embodiments are given by way of illustration only.